Feature request: `attw --from-npm <pkg-name>` use `$(npm config get registry)` as its default registry

Currently, for me, my npm registy is `https://registry.npmmirror.com`, not `https://registry.npmjs.org`. But running `attw --from-npm ` still fetch from the default npm registry. IMO, there are 2 solutions:

- allow `--registry` option for `attw` cmd.
- if not pass `--registry` option to `attw` cmd, use the result of `$(npm config get registry)` by default

Start by tracing the `attw --from-npm ` command and how it selects the npm registry; compare that with the value returned by `npm config get registry`. The work is done when an explicit `--registry` is supported or, when omitted, the configured npm registry is used, with behavior verified for both cases.

Written by the indexing model from the issue text.